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Old Mar 28, 2022 | 02:02 PM
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Default LS1 Block ID

Ive tried to track down an answer but not having alot of luck searching the forums.
I have been told there are differences in the blocks between the LS1 years.

Im not sure where to look to identify this block. If anyone can point me in the right direction it would be great.



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Old Mar 28, 2022 | 03:31 PM
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on the front drivers side the displacement should be cast in there, and the date code should be on front of the block in front of the passenger cylinder head surface.

https://www.onallcylinders.com/2017/...ads-cam-specs/



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Old Mar 28, 2022 | 04:03 PM
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Originally Posted by theunderlord
on the front drivers side the displacement should be cast in there, and the date code should be on front of the block in front of the passenger cylinder head surface.

https://www.onallcylinders.com/2017/...ads-cam-specs/




Unable to find that.


this is the only noticeable numbers.
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Old Mar 28, 2022 | 04:42 PM
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Originally Posted by theunderlord
on the front drivers side the displacement should be cast in there, and the date code should be on front of the block in front of the passenger cylinder head surface.

https://www.onallcylinders.com/2017/...ads-cam-specs/


dont have any casting marks there. Just have this

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Old Mar 29, 2022 | 08:19 AM
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At first glance, if it is a 5.7L block, it looks like an LS6 block. it doesn’t have that column in the valley like the LS1 blocks do.





Are you sure there are no casting numbers? Double check the back of the block around where the bellhousing bolts on. It should be one of these two spots.




Last edited by KCS; Mar 29, 2022 at 09:03 AM.
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Old Mar 29, 2022 | 09:16 AM
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Originally Posted by KCS
At first glance, if it is a 5.7L block, it looks like an LS6 block. it doesn’t have that column in the valley like the LS1 blocks do.





Are you sure there are no casting numbers? Double check the back of the block around where the bellhousing bolts on. It should be one of these two spots.

what is that arrow pointing to?
at work currently will check again when i get back home. May have to scrub that area.
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Old Mar 29, 2022 | 09:28 AM
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Originally Posted by Austin.VQ
what is that arrow pointing to?
at work currently will check again when i get back home. May have to scrub that area.
It’s pointing to a little column that was cast into the old LS1 blocks. It’s significant because you had to cut it down to fit an LS6 valley cover on them. Heres another photo from an old “how-to” article.




Like I said in the other thread you have going, some of the other photos of the block show some things that make it look like it’s actually a 5.3L block.
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Old Mar 29, 2022 | 10:51 AM
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Originally Posted by KCS
It’s pointing to a little column that was cast into the old LS1 blocks. It’s significant because you had to cut it down to fit an LS6 valley cover on them. Heres another photo from an old “how-to” article.




Like I said in the other thread you have going, some of the other photos of the block show some things that make it look like it’s actually a 5.3L block.


Found this

If I remember correctly the design of the backside here means it’s after a 98

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Old Mar 29, 2022 | 12:08 PM
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https://ls1tech.com/forums/generatio...hat-block.html
"12560626"

there you go.
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